SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '068aba5326ba77eaaf8dd6cd640bd0b966980123323a2ad1ab77439b69fa0b07' 
  AND token = 'lFZugIAupCTmjUt3VdkXkzq57a62+KE17/TTmniKwM8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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