SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95718afa260f9d12d2531a017c78872826d07352e341ece6d38cab866e7ba405' 
  AND token = 'ZMMV6Dan65FzSoYvrHHX3lZqLu6XKHKHrTvlYyHy8PQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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