SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '346960e47444bbe6bad5436a1be82c8e31551ed5f20cf102a81882026801479c' 
  AND token = 'ifVZTuEh+6B2955EyfXE68RIvbbDiuEQWP8/Mi8Tlek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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