SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8ab262ec852247f556f451e16cea9405ec9dc2bc100328d236466b5ceb130a35' 
  AND token = 'ITG447CXo4JVMgk/ryYUEvUAvPuY8W0c/N4aU5HvUlE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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