SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b449377c3ab9184d65835ac566822910376adbb0f640241a854bd7be25db0c3' 
  AND token = 'aAiWL3/TYpV3z6x2++Hcee9lp8lh2Q+3rS1zwvJhGO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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