SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '956ad9f09d6a7eafa4eb654ad4875e1bbcee7514f09571a0a175796a548ef921' 
  AND token = 'eBtUq5m2qVRFLrduNQy4B9j/6G7k8ZYfYQav14w5yNI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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