SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdaa7fa490cc344dc31f3636b37badaa1dd30736b3e03ba336e4cbf842a2a9fd' 
  AND token = 'Y/xcOG98FCPTKW65SYdoqsNwiaUSTQoIXZqRqbR6WOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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