SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1dc5801cf9c111203c19b665a34f36108c36a96449101320158c52d48924a342' 
  AND token = 'sDVZ0iRoCqC1lTE/qm4OKv4gA0KEDtYWYPmg8u9qWi8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}