SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd82c93f51e4711187cd916cc1955c5b2fb2c4815651ba4bf788eef6b69f52f5d' 
  AND token = '1jFVEH8ZMSRDzlofsAg6sXcY+HWmdPqxJJiUC3CkUCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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