SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f790e32e83375e15ecc8a144ad48f83d8941643f4413a8c88fb37f995721ff89' 
  AND token = 'wOTmTdEGU75Nq2llsXGRlWEMAWx7RZxbOQDWamW8T5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}