SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53ab504caa1e30e7fe55f186b34282581f3f8c247b24bda3e69e7ba490881b5a' 
  AND token = 'hdoFgnBJIhHah4lpt68Tpg6lrru5WcTch6qLDruApLY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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