SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b9904d1d38a606ad18434f45655231df2dabebd0046d788a2257a714ba910b38' 
  AND token = 'SYEwt27x0fQr+d19AvxVGNPwCM0JCfeG1/WbFUUbq28=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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