SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c83ceb11140c6dca1bb3ef3451763313c042fd27aed2752172d98ed2693b500a' 
  AND token = 'CVsMwNkyH3pkoOSsqhQWMCp7w6HdGIrgMJHO57AE6Y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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