SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb00e9f6c95a93acb0758473099401fa77b6137529389b75683c7489ff8867df' 
  AND token = 'Ye7osS9sphArSZjWRrtPdY26A/ffES8MrCfS9zVNX60=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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