SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '16f9fb9171dddc6f9507338482458fa0846158d1b992e6e961c9fe5dcef289f1' 
  AND token = 'Spqne/0NWGBMEad4fgt/JoCUzktXsIMPEHse7l2Kh1I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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