SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9357fdec620b7f057b99149f490bdf090e48c3d095b574750951eccc5a7cdd31' 
  AND token = 'qSgwK7A315HaanhBS1Sj5c0OfFydQjw+5jN2f2BcDbQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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