SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d5df204766f6a8f8b9159668583d9f97b43b95e62e4c873e95def62d49979e0' 
  AND token = '+vPhTys2wknaINMJgK3gNqw9w3/ZyWebUgF6cZG+Pws=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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