SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd2f632076b545dc39848f35468e57e8655c142e545888edc3c47307b24b388c' 
  AND token = 'GNiLSjQU6tPZCmBDAcyZJsn0hh28J59PW1qfFXnyz8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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