SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '296ecf038787afc617b7ab2e475d79a23a18d25fc38c9e96688d632e5a10e094' 
  AND token = 'nEmo9cGx9n1QKUDwcyfKN4slnrEr3WPIuY/Kq0SNhUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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