SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b25c6553fc468076d5123c2c3b757b5621e53170ed4284837ef64cb19b2399ee' 
  AND token = 'qfssOuDIxli0QXIwhdPADCwhTEgHvPK171cSvrtxH7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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