SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c8666ae7516d1dc9253a35b2738ecb33cb0669220622108cf33c8416127374e6' 
  AND token = 'jpJwKh4DcFVRrI6mbpPtihs50kJxXpe1U4cscRRuauM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}