SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cd34bc731407d64970925f14cd1e49d885a7b22e9ff89fad1b4a0589c55dfb90' 
  AND token = 'WlOEmPvew0QyhjUJS0IuW55sSiNEBmlAmAFKRKQ/DLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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