SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39acdb139752b81411b0063b76d70b2e847b8adf5afbdf87078da810ce52c7e5' 
  AND token = 'TeflQMvsgnhU6/89+MoM7KRadS0BvL1KOgre1LPNmkM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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