SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4564da7d47024aa61377ee7f760031826d534a047ea9be4faba708bab6f58d0a' 
  AND token = 'nKIU1gGGyEZL87U38qeXOT8+Do1ViVZPcRcMOF+6opU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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