SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e2546230db97c00219a6f46e711172b41301ba5212bcb44d0e0133769928e65' 
  AND token = '4xggcC+JeAYEOjarYywLBoTHYsLzd1MjYNir6YKbuiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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