SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4df5776b3ce64ade8da8da859871f274c20d6b70fad8216980e486bf797c5759' 
  AND token = 'Fi3ZLuJbX7dCw6DTN05fttL8IpXwlat4rgGIoTyud8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}