SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e2de717ec83954ad9516f5dc485a32316af5666bf9be19761c57bda59a7b280' 
  AND token = 'pM7DgokFHkXEhRJLNVZsnzhoix4brInzRRy/jpyGt24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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