SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5a65b93a7385f86e31187f55abb3096b2f2bef00af72c66345ee20328d170c50' 
  AND token = 'Vv9hVKA4TqhcXkpelkz4wUJ6uJUmaNVtO0u1IOrk8Sc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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