SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '962782fee5dbaf0f3027e731a49ef1d6dfaed72619ac481b6a5cf79b64b94f63' 
  AND token = 'l59XLKTIGCAsu2AeoQzxDhMAlvmEQFmBR8HMQTr9B/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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