SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '136b0d527b8c9bcbada693370c1945461e72e71f764d791859763ec13313c201' 
  AND token = 'A6mQWmbc2n8mb5doQcvjU4HWzkOuhz5FLacWuo3vpbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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