SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de1e54d043fa81f1bf48bdab777baccd18926fa471c4bddf22ae9611a9cb1f2f' 
  AND token = 'pTY/ERfbGdyqDUxlAazc+ZMDR89OOw07NZs9DR/Bi10=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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