SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '450f076bc2d84377a024e87b39b6e0184535dd5d471ebc4f94574594b52fd77e' 
  AND token = 'HHUOwIw1SlgfqDn0StInoeehpjKZk6afMOPcu8uF4Y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00057

JSON explain

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