SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e9d648bf38f7175b0c796df78cd7b83982d8d84ccc68f1bc17179d76a724679' 
  AND token = 'mcAs6sr9EnajM+iCSYR9CnhA0WjywbiXcO3hsAwijoo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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