SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b043531902598bc9264780302c23c03ad58c68521644ba5488c53af8c800a1b7' 
  AND token = 'DtjexGMYIUBhrNFUHSOsBWh7aT3a8BcXam+aAF1Crk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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