SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40febdf45a01675b7836e2fd853fa481407887cf910e40d57100fd9be5c75286' 
  AND token = 'RYLc5jcmJu1o1/VTqG8FOK2PenLuVrcsyjz9YtYMs6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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