SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4b17023b30a70161cdcb3624dd16fb161ac5982ef62ceb8299af6f3cb052c53' 
  AND token = 'wWeWMTt1g/cfxvPrAEgM2oGbUlRenBFPVfIVWn/vznA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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