SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1269cd78fc3c54bd7252ecfa8e147583497b00ad09f660448f150d98b0f5bc0a' 
  AND token = 'UIBzJ3IsBYpozb3MDhPxnqa9NILbaOrJpAwa3BKazD0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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