SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc4235a4763a388f627387d829770c64f8f0a7fbb377fcc1c1d3d7d80ba75611' 
  AND token = '3uhNtmHKi2+vtIAqBw/gvSN47LlZAVdoz/n/bCatEC8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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