SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dd76367b152bc592813b36a0a6fa001de1ca04bdc650f5620313c50b3f2cb49' 
  AND token = 'NhlMX9nnL9+/y57LxuVKDSFpQgD4eeQGLD9JSYutYw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}