SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5385b288d71e01bcb6473077c401ea9547e7c52c509399800119b0d737fb1a4f' 
  AND token = 'dAx5RPU1PAbdT5bqfaFdJOpuFc7WzFnejFfQykoFdcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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