SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb6a7dc2c990af7785ee741244eec4ee700c44b8b1a8104bc5630e9518c47ea9' 
  AND token = '/CXpDd5cAoKXDnBROgHaw6lIkhIRHysikykEmfFIyK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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