SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '62b5390745bd4940593627eee89d3905cbba75ed7d61674ec7a70059fe8e3eeb' 
  AND token = 'qF8IKubEdGK+Aar6mTwLzJfrH86fCdduH3hWphd2l3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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