SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beb20b531aeaf022ba37666f2a0b15420264e5cafb839311544c20023d038644' 
  AND token = 'ZrI1V8C6EsBOcoy6XTWSMkcfHywTMX3xVmJFP/OiUQU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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