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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f50a6377499e1fa658aab2372908cdea9fb15ea04b449b0ed1bd7a0a483da04f' 
  AND token = 'ydheY/9ZOV00Ye8UiU3E9bf9hkkqk9k168p+Yg8TFx4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}