SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b28b48ac12eac05d9639a5b93ff515c729dc6b8208f3e2f25aa6d24977ea7630' 
  AND token = '73V46yXBzRwODlVmt/ZL+Tcwnd69C4hR0rKO9ibhfRs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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