SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fddecd4bac20267edd4f068116d36fcd6f7ead8530ea7975ffb06178d5b82f29' 
  AND token = 'kiEpHfDAr3iTUkH4zsywneSbspBjMtLQM8yHQWTSqBg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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