SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ef4bfb5e0daea7b015f374844bbb59314759f5ad9d5f7f2f48a2b16ae04531c' 
  AND token = 'EHPX2MttUueuxFRmntirwTtwN+eLceurnOJS86fJTSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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