SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '804fbd6a0b2e294b532b75bfe546e0e1f816d19d0faaf04b85cbcf35a7926c98' 
  AND token = 'VHYcIwspIu23bjqOGHOXUAntl6jLgTmi3eALgHhZUo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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