SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49b81cf6ef2f91d0f52858a6aa14fd44cf4b9b3387ef9d28253b04d067b3d32f' 
  AND token = 'lBpJS1V7H/rOGjRsUetQQOY5NTXHdmvLecDWist4zSY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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