SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f04d5b31b55836b58c7bc03f520c9789f6bd97d075ccbcc1df81f66911c90814' 
  AND token = 'zE9DWtQUN+T97ph3KbgomXWjDJ/Fvw48CCiLbg5aoZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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