SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ec86cfb940eb148f349df2e3ef100a8237bcf8cbf18e3d4ee63f10703ff4f587' 
  AND token = 'n3gump1eyb9OM1w5c6OTMBULZddW1zzaw6BqoUQO0Fg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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