SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2d38dd8b1c4cd9e623f0b627ac7cc204e0545ea422891432a885bc016f1fafa' 
  AND token = 'XbJrZiyj9rLgUJMmS7wdA36HGWTQ6TEgsIxfqcMJO7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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