Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b5f88e811fa89c2e762284b2b68fbfb982c004b8bf079813fb8bf8d125dc9d43' 
  AND token = 'MAJ3Ce+9EwgEt4tTTzNS5zZZlN6slBnXiPfQY+0KZnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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