SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '067b4ab00548a2a83456262352e60ffaf9c40953a7b1448be4333ef6035e96a5' 
  AND token = 'ljuUKrJelgV+bKHbrxosdkNFFqI4TeY8uHcGHSY413s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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