SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c08b622e18811e2120f0860377d890da13d7d931163db6e5652cb27c5b83b74c' 
  AND token = 'BkdZjnekV3U2aT9AIHWtO5d3YkD9oN+gUee7jR/0vtw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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