SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85ab9ef162a2f6d5683c01d17ed85f99917c21dc18eb5a0a976a72859c344941' 
  AND token = 'pZabwMy3geZdGP+7YruJuNgeXHonPTBHMhk/FAbcb3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00054

JSON explain

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