SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1717178a48c923ca6cef2873baf38cc9eb843a198382e7df469d8e7acaf685fe' 
  AND token = 'cmrjNUNU6agL/+5yhlaWdAijmHkEH03MsJMazxE00uM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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