SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb5d0a8fda0fd644c0d5e766e46070c35bd17af31451f3277ba826aa39c90d07' 
  AND token = 'gJAwyIR4JDvyvTX2GSVk0QrYv+PcFnwYSRANzx8AbVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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