SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bbe7e6626bcdc14fea02f09fef9f0108b166215719c8362a7e3fec64c5077f0' 
  AND token = 'SdnChZv0hz8W4pCOjJhwfywoMBA8KbYkTjMSgdPAmYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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