SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0827ad0ba14f22e0f8357e406913bf09d03b541f57627ddb91cadacbda4f61c8' 
  AND token = 'vgEGnY7hWPr4yj9Uj66MlhFxtMM+L64tGT/xuw14l2c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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