SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06926897366c5c4dc9b98e8614950e59ee7d375e314db412f1294f34c788ffec' 
  AND token = '4Xr2JHSBvYchAmpTFzXPX9KW9LXiU1fVdFPHpKATbgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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