SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79d4c6d61249466401c50d7b55cc818862d2d98b582d5cb8ac25148ca6ef7be6' 
  AND token = 'HAgNX/eaNunOC6pkDQVkfCExdPIEooawjod8joF+m0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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