SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e2d73ce5746fc900c33b526523964138e3fced637ec313ac64e61a11f2d0cb1' 
  AND token = 'TbyAs2lLcOCBk7eV9WKBxlnsot7rPuI9NjbxSgU8yz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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