SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66fd23569e878381ddf8fd27d7a02b6585396f38487972ce64ba1ec4454e1fd2' 
  AND token = 'nodDRCTGXjvVnUzIckllBdYhmV3JNcR4kgt9bd3OTKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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