SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '513fc2bcb7f2c3994a9918170b31142bd6601992bebd657f54c91a8418133c00' 
  AND token = 'EwMRBOukaJ+7+CJPaQPBntZB/KPltPLeRkWGMLxa/Ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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