SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3566f1c530d6077a2ffc2c15a43520ea95e6abaceffa305feafd64fcdcc19838' 
  AND token = 'KLJBZMUebjvQTErriYEiEnn82DQ0gNP6SyfIDQ53Xdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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