SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6b96f1f15608dd76c069a390dc91205d36e7e0825c67863e0f7bab908baabcc6' 
  AND token = '8XkJmPETUCPYHLAS5BtBicdx4rmLLTE8gR00IEU+XO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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