SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'efb4e8e02885dce8c6af4f7a996afad2c2fe9adcd1dbb636550fdf9fd0ca05fe' 
  AND token = '1E5D6bJHUV13pHqyLUhfBdU2nyV0q5UaatbpeLbHWCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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