SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82babf964c73f57c9c020f4fe4b9c51ce2a257c7e8a8b56b5b666d51594582a4' 
  AND token = 'Ot8k/3iRUoF5Zf0p8mnq1D5GOu2sSjdM3rQh37LpNx0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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