SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1cd6c459bd05fb537fbff397ded81f2a429c6c7bb7e4af19d940466bc004a2c7' 
  AND token = 'xaRCnBg90+dHPUDoOjhB/YzFE01S5KEpG3we60S6K+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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