SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b4c4f4d3010e430ce110abeda15d6168f90014ecad8101a60cbfdd1652f48297' 
  AND token = 'jbqijmioSQSXVtOAdr178wCxuLvAGKb53XLpB3xoufY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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