SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b80e724e0da78b973d1297757e5e714ff690307b3d8c17796afdcb7042aa143' 
  AND token = 'cXTTHxs/aPRGeKtMaMSfgYnA92wNyCK4YPjkzxkSc8g=' 
  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"
    }
  }
}