SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd1f9e2b4cfbed7a63ca3b385d9e9f6af53dae9bcb7cc04881bc91148e431e64' 
  AND token = 'Vl6LmwGDflKLjqfnbYSbIJZECTJZqSHfxgehN5lpcOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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