SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '352c64e2bd4051c57d60e03ce2d3256c3abdd1d5051d1db97546528284b8782f' 
  AND token = 'KHg83pWfZVxd/wSkoyAtcas7ZiOCdWGf6CefF0HuDyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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