SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ca977089f24fdd8987b3e4a8c35ec750f158f2bacbd47aaeb8853408e2cc9a0' 
  AND token = 'nmwSNsg2jJP7jm53EzUwJRMkZMtBRKuRSEHrmP5vXQg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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