SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3baeefa2ec2127405cda3d755ceab9278e0db5a4bc464e49d4c6460fa303ec92' 
  AND token = 'SmMokOwlte+AjWUeiQi0NymCxBMrmL6aA0tftSQW2nE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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