SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '768fd8724fe77051c4a8ccca089cb31d89a173de4ba3a654553329c486ac7feb' 
  AND token = 'k7RgA05n5PSkBFLjZRKklxKqB3tcYiQW9yiT8gxWOHg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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