SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cd36a51fc357585fb6c535f7bfcdce58182d3407ee35159b9f10c3d9578f496' 
  AND token = 'ziOCbAF4SeKZ1JP7KpTwN6HbNymsHYOwhQUiwijje34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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