SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af0b931e811cb48814c3dd25838cf5b9b0a886f3983657d5566f620101c4ab9b' 
  AND token = 'GsVBc+EO9/61NFGJbuTlavEwPBX3bNypk+voctW+Gww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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