SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d8fa494686a2e647ef9c01d7fe752c5d9eb6436b17f45d034c1386ac987f905' 
  AND token = 'GgtNNpOzUqnvrvMGfJbZMJL87hpfWLjJcJv1uVefez0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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