SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bbc5ac0eb5c2529a510c9bfbda93275245bc37d8c08753db4376136729d9d8a' 
  AND token = 'QPVfd0oflQlMCzwQjcDGTPHUL04WgTgOvNYFAJWuUHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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