SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e25ea6064159dfdd943d69659f67299aed0414f16cd205fb04b6ba4ae03547f5' 
  AND token = '2prozYGBsuscX6jKb4RS4iWDFpbjQJ7orhn4aGy6s54=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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