SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f4617e72a4efa6604a2b559d23b027adc5b74671da2b5c9975d8f8cbc3bfd2ab' 
  AND token = 'jGlyDTE/ukTuoFPK2zQLVnCnGYyeLsBsu0tG5D2RQps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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