SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e342febc7d5f6851d1d7aaa8c6f2aac63c76ca7a66fc5e6324ed2ed92a1a97c3' 
  AND token = 'YFaUn2iY6gvXSorZTD69MTbPxCIdeaXsaiWkwDknQjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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