SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e04e311b58b20833fb71aaa3aac79eedb9f3e8a62f92dca7e5945f0de800860a' 
  AND token = 'j2SmEcgsP6wezQoy+a3Q0AvdK/y2RJSe1WY+cNS1NII=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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