SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daf55872e5ed1eff44f76e134a06fd8e1690c43aad4f076f2b8eb2ba5dabc0a3' 
  AND token = 'Zq9sgjyj3jwF0tv0FsQK+MxJhYDSDdhfvvi5tkhJu4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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