SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed03db1f7a8e5efe7687a52143bcda594e8ca39698f2f3d737901f3395a421fd' 
  AND token = 'tlJrjTOuk6UMlUEgRdkhbdcVfTEBOw/zqDwPATwz5gY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00125

JSON explain

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