SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '312967545617df92fed25e181e60fb2a4496ff3731b5e7c61bab420c86788454' 
  AND token = 'QhKdzr6CSYDwtiuaWB+gtmllpviY8vNvQJVpTfXJR2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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