SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6043dd5cec6f6c41a64498cae74b755286300381dcfa1176f19426e832a774e5' 
  AND token = 'yxS+xs0Pygiz6jb/+fLAr/Z6tNsmDvefPXUvN7Ad76E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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