SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40ca3fcb5bdfe3195f0013d1744b10691e83912228b0eb5580583519c9bb655e' 
  AND token = 'H/kYBoCAC3meXIYubQ/0TUkTJhgUbMvIrEX5nqAPSjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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