SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd77fe3f8f4ff00ebe420ff86ffc68a97329f1277ab14873eb0c29fcd2339438b' 
  AND token = 'rlxI6P+lqyMN0IxJsI+2GgrYlepN/P7ZNde/sLxDYFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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