SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd1aa75496c0fbe090bbfef5004c358a54d27cd2d42e62197a4fb837f9549f57' 
  AND token = 'hzx8ri3kdWRlFwijAKLYCiw2JoFKZV4EUmr0Z7/sdaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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