SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e9610394e71ddf95fa77e09f602a38e45e453132e12dd280606b97926e01108' 
  AND token = 'q+8GzdGuTplhkuNM7ybvvHbCdNIFB0z4Wox/C5r529g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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