SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2349e0cc1a660aa83cbe6db6846b4664d608ff7aaeb0b8d3d56a939634d401d3' 
  AND token = 'oIsC6KxGIhNXEW8l6NuqCYVdPoGDbmcPY6EVMP7UNFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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