SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89e2b5d196b33ef3cfb00f878c5109d45bfa3a46662e8a215aeeb515da34749f' 
  AND token = 'TCFtGV8x9j2xmEWo2EY3yPgT9MqKK/Ou1jkjahdHhDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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