SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e64ae9a7d88ad0660defa5e9d6c70f822cd0541ee6509fe10550bc00f0d2c3d4' 
  AND token = 'Yb3DWEKtQS30e732Lt6pyZvWzlFfo8MSHhWkgRzvsbk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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