SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98306ea847c9363462af4a9c325fc46cbdda53d44cfd728f77bc4716fa8c75be' 
  AND token = '8KkiZPfOO6n/vWIWN+fsFvIPcsJpKy5glpssjaBFUlY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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