SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92d950d6a4450d5ae1fe1be0f298f70ac4a3adc709a71e6534686b12107d9810' 
  AND token = 'l5AjKjgqbVEZcQhlAKrl+HbL9Pkaz9VxGqG9VQNhOO8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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