SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca7a2189b57ed2bd63d6b4706753715ff669b3ee36c2223adff1838e544cba8c' 
  AND token = 'hA/3tb/MpDzTGK0yVemT9O/1FwzB9rJgENcsWQftwa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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