SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bd9d2d9f9bcfa3c9639d5452db102f7b6c66dc7643818d5d10844c9432d1ef7' 
  AND token = 'bSPCIKq6UAmgnFBIClMWRt/pHAah3oM2tZTOkeQSYXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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