SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3571726068d07a96f1ce1d875ebebf60cd1e7e17374b0ac681d055e7150f796' 
  AND token = 'rCB9EWEAq/sd/P3cHux5iS3SFM69BGhzTRhrxLECNS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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