SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a445bf986d3543f8965c5274067fed9d76dd452a906a42d41790f156ab7454a7' 
  AND token = 'nTXleRFjZnlsbRyVs0IUj0yw7szQfILWcYuzbJs4Bck=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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