SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2d7a06c4e60105e47a109944f68b7922fc500664422a46627b01b557f1e5a1e' 
  AND token = 'OzJb5T/PqjN/Jo7K3S6QMd9cY79LKAY6chugID0JXAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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