SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52d45132dd90f9275eff93fbc3ee5a6c242a7e742bf6bc6d8d649aecf164defc' 
  AND token = 'YUp2BYuqOJLK7pXtUU7PM+5eyxqe8+pLk/13z4GZ1mE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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