SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5b2040b9789a57d541e8481f3d038fc3823c498e546a5e69185b60c649ad2d98' 
  AND token = 'ZHlGW3OgDUhq+swAU6RIEGV8qlA932LvudUYrH8cR2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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