SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a5aca6fc80d3d8ae4b017103f148f25e788340ed53e1bf47d16da20f1f72df9' 
  AND token = 'XQxH0nsnxJ8OMLLsXYCXLbMYjdNf4AbfWtYBsulFttY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00079

JSON explain

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