SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f087c35e9084817cfff87c2c2e398875e1a8489ec274e3128ce529ea92d12c46' 
  AND token = 'XMvfJx3MJkth+7RWjjvvSGeyNFZNZgf1bxuQFM5DTyg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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