SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f87e89dd14e85473a2f5795405675dd8341e45e23d9f6aa06f479be177ff0d9' 
  AND token = 'fXdaL4j4vzHvrW1+s3g+IhVqMPhgw9RPVIB2XjKol0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}