SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '20098dde65cb1856f010d58fd04a01f7540f18a66827058f52a0f04bbbbb27b8' 
  AND token = '8AYS4RDK+5sugcFvU4tHAp+Gic8DOHcwuDgo2iOiKEw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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