SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9969a106263acff96522f43003c24e11fdfa83eb0ece2fe31a50cb6738666dbe' 
  AND token = '234i2lZYZvihUmS884t8U2QJNp7CleU6sJ6Y3Nd/Wgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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