SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e895490112176f392f9bfed89e4e1ce58ac06ab5dbb350c33bd89a67ff6c1853' 
  AND token = 'YMCTKAEkoMQw+ALG0855ogwlCMzi78FNbtO2ZuwPBb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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