SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d84ec9288acb548c7fd12a22505999e2a066ac92299bab5dcf456622ae8c919' 
  AND token = 'tirJ9Rl9EZRY3jcqH3MSQkDCabMd1DeSvMhdCCTZ+YM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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