SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9d1068996e610e57d000d6becb7ce804fd6c5797667c83015af2d3be0938577' 
  AND token = 'uKjQTH5TYOHxiZ05w6Jzv5j29SUGpv7BV5xgBFVETLE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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