SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e9dfb1a5d6d81067e396043d6a5dc4f73e77786e14804037e659641c2d22a172' 
  AND token = 'sgz7JuPZ5mK+PZL/ObIrL059mblYxl/EyVV33qXaG1g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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