SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0bd6eb7806d6c22f3a054ddccfbb43f6a61540fb238f5b0902407d17f1a534ac' 
  AND token = 'Dxyktme0GwwryupYb2VO1qm0MoXRu0w9SeCaBgIqkAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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