SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fad58c8862214a1edec3f63a39c0ddfdbc67a26a8737883cd6579603bb1b585' 
  AND token = 'crGVOQDwHdZnQWjCKfLye3Qpqjj+J9FRhv6NBi/rTXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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