SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '549d33a6f27630edbe927bf99430d405365474b817f6106218c81eed78d6a284' 
  AND token = 'GnxTk816U37JJq7QGYZQmphKzUk6EiUuddSo/NHs+Rk=' 
  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"
    }
  }
}