SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9883af522c3fb5a62244ba938556f2e5e9621991f10fd61f75d3753da56c005' 
  AND token = 'DsuTeJRJJigbezSRAHbZx1dgm5jQY2MV1LgOtlPannw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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