SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6cdc8c9c547a875a4b96822501f303ab514f2b70cbc84ece86220a21f47859d' 
  AND token = 'udgFU+O+v6fGh9CYu8/xTIW6iHqNt8S9VWWeQqakwzw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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