SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5dd10b1ae0ba86915f2f865323a7fdd4d8ec93f141b4bc26a178525c0dc1825' 
  AND token = 'FhXv4j/z6Y/3scCiszPbbVXyqxEqZnbIZ8B1wTdRzSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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